#include <iostream>
#include <cstring>
#include <algorithm> 
using namespace std;

int main()
{
	string str1;
	cin >> str1;
	string str2 = str1;
	reverse(str2.begin(), str2.end());
	if (str1 == str2)
		cout << "yes" << endl;
	else
		cout << "no" << endl;
	
	return 0;
}
